Delgado was neutered at 10 months, my contract with his breeder required by one year old. It wasn't hard keeping him but his drives did peak several times, if you're committed to a LOT of exercise and training it shouldn't be a big issue. They do need a outlet.

Otherwise anytime after 6 months is ok

For maturity most people say two years old for males. As for the "male macho" look - that's more genetics then hormones